The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1998
Filed:
Jan. 03, 1991
Jean Nicolai, Aix en Provence, FR;
SGS Thomson Microelectronics, S.A., Gentilly, FR;
Abstract
Integrated circuits can have both a microprocessor and an internal read-only memory of programs on one and the same chip. To facilitate the perfecting and finalizing of the programs of the read-only memory without undertaking the manufacture, for the perfecting and finalizing operation, of a special version of the circuit that is far too different from the definitive version, an external memory is used for the perfecting and finalizing operation. A contact pad of the chip is used for the transmission, in series mode, of a program coming from an external memory. A mode selection pad makes it possible to define whether the microprocessor must work in internal ROM mode (the normal mode) or in external ROM mode (the mode for the perfecting and finalizing operation). The circuit elements added to enable this dual operation take up little space, so that the definitive version of a circuit can be identical to the provisional perfecting and finalizing version, except that the definitive version contains a definitive program in the read-only memory. The content of the read-only memory can be defined by a single mask and, consequently, only a single different mask will have to be made for the definitive version.